The objective of this project is to study the mechanisms involved in androgen mediated or estrogen influenced gene expression in the rat and mouse seminal vesicle. The genes for the major seminal vesicle secretion protein IV and V (SVS IV and V) are under detailed study. Bacterial clones have been identified and characterized which contain inserts for cDNAs SVS IV and SVS V from rats. The cDNA IV and V were shown to have unique sequences. The androgen induction of IV and V mRNA in castrate rats was measured using the respective probes. Mouse poly(A+)-RNA IV was shown to cross-react with rat cDNA IV. The chromosomal genes for IV and V were isolated from a rat library and the SVS IV gene was shown to be about 1.9 kb with two introns. Another observation is that the SVS IV gene has an insertion of approximately 200 bp in the second intron very near a rat repetitive sequence. This insertional element may define an allelic difference in the SVS IV gene. The SVS IV and SVS V gene are linked and a detailed study of their 5'-flanking sequence is under way.